Detection of vancomycin-resistant enterococci in samples from broiler flocks and houses in Turkey.

Vancomycin-resistant enterococcus (VRE) is a global threat to public health. Knowledge about the occurrence of vanA-carrying enterococci in broiler and environmental samples is important as antibiotic resistance can be transferred to human bacteria. The aim of this study was to investigate the presence of VRE in broiler cloacal and environmental (house) samples and to genotype the isolates. In this study, 350 swabs were collected from broiler farms. All samples were plated onto enterococcus selective agar containing 6 mg/L vancomycin and 64 mg/L ceftazidime. Minimum inhibitory concentration (MIC) values were determined for vancomycin and teicoplanin. Vancomycin-resistant Enterococcus faecium (VREfm) was isolated from 6 out of 300 (2%) broiler cloacal samples and 13 out of 50 (26%) house samples. All E. faecium isolates had vanA genes. All VREfm isolates (19 isolates) were confirmed to be 95% similar to each other. In conclusion, although 20 years have passed since the ban on avoparcin in Turkey, the present study shows that VREfm isolates are still present in broiler production and especially in broiler houses, and most importantly, a major VREfm clone was isolated from broiler cloacal and house samples.

Prevalence of O25b-ST131 clone and fosfomycin resistance in urinary Escherichia coli isolates and their relation to CTX-M determinant.

Escherichia coli ST131 clone and H30-R/H30-Rx subclones are the most common multidrug-resistant high-risk clones in UTIs. Antimicrobial susceptibility of fosfomycin was compared to five other agents in consecutively collected 299 urinary isolates using the agar dilution method. Prevalence of the ST131 clone and the occurrence of blaCTX-M were also investigated. Overall resistance to fosfomycin, cefuroxime, and ceftriaxone were 2.7%, 35.4%, and 30.1% respectively. fosA, fosA3, and fosC2 genes were not detected. In isolates resistant to ciprofloxacin (34.7%), the prevalence of ST131 clone was 31.7%, of which 81.8% belonged to H30-R and 66.7% to H30-Rx subclones. None of the isolates of the ST131 clone were resistant to fosfomycin. However, blaCTX-M occurred in 57.6% of the isolates among this clone, 62.9% in H30-R and 68.2% in H30-Rx subclones. The results of this study suggest that fosfomycin resistance is not prevalent in urinary isolates, however, blaCTX-Mpositive ST131 clone is quite common.

Presence of OXA-48 Gene in a Clinical Isolate of Lactobacillus rhamnosus.

Lactobacilli are part of the microbiota and are also used as probiotics. However, in recent years they have been associated with invasive infections, especially bacteremia. Lactobacillus spp. are usually susceptible to penicillins, macrolides, and carbapenems, but Lactobacillus rhamnosus is intrinsically resistant to glycopeptides. The aim of this study was to determine the antimicrobial susceptibility profile and resistance mechanism of a clinical isolate of L. rhamnosus isolated from 10 sets of blood cultures of the same patient. The isolate was identified by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (Bruker Daltonics; BD, Bremen, Germany) and 16S rRNA gene sequencing. In vitro susceptibilities to penicillin, ampicillin, imipenem, vancomycin, erythromycin, clindamycin, and linezolid were determined with gradient test strips (bioMérieux, France) on Mueller-Hinton agar plates supplemented with 5% defibrinated horse blood and 20 mg/L ß-NAD. The isolate was resistant to vancomycin and imipenem. Polymerase chain reaction test was positive for blaOXA-48 and the presence of this carbapenemase was confirmed by gene sequencing. Although plasmid analysis suggested that the blaOXA-48 is chromosomal in this isolate, it is still an alarming finding for potential transmission of antibiotic resistance genes to other bacteria in the gut. To our knowledge, this is the first report of the presence of blaOXA-48 in a Lactobacillus spp. and has utmost importance as these bacteria are used as probiotics. The isolation of these bacteria from sterile body sites should not go unnoticed.

Streptococcus mitis/oralis Causing Blood Stream Infections in Pediatric Patients.

Viridans streptococci are still under investigation concerning epidemiology, pathogenesis and clinical presentations. We aimed to investigate the clinical presentations and outcomes of pediatric patients infected with Streptococcus mitis/oralis. Based on the accumulation of bloodstream infections (BSI) caused by S. mitis/oralis in 4 patients in our Hematology and Bone Marrow Transplantation Department at a particular time, a review of the medical and microbiological records of pediatric patients with positive blood cultures for S. mitis/oralis in the entire hospital was performed. In addition, a retrospective case-control study was conducted. Pulsed-field gel electrophoresis of S. mitis/oralis in 4 patients displayed unrelatedness of the strains. A total of 53 BSI (42 BSI and 11 catheter-related BSI) were analyzed. Thirty-four percent of patients with BSI caused by S. mitis/oralis had febrile neutropenia. Clinical and microbiological outcomes were favorable and infection-related mortality was not observed. Although not significant, previous antibiotic use and trimethoprim-sulfamethoxazole prophylaxis were more common in the case group. S. mitis/oralis seems likely an important agent in bacteremic children who are particularly neutropenic because of the underlying hematologic and oncologic diseases. Prompt management of infections with appropriate antimicrobials, regarding antibiotic susceptibilities of organisms, may facilitate favorable outcomes.

Human bone marrow mesenchymal stem cells secrete endocannabinoids that stimulate in vitro hematopoietic stem cell migration effectively comparable to beta-adrenergic stimulation.

Granulocyte colony-stimulating factor (G-CSF) is a well-known hematopoietic stem cell (HSC)-mobilizing agent used in both allogeneic and autologous transplantation. However, a proportion of patients or healthy donors fail to mobilize a sufficient number of cells. New mobilization agents are therefore needed. Endocannabinoids (eCBs) are endogenous lipid mediators generated in the brain and peripheral tissues and activate the cannabinoid receptors CB1 and CB2. We suggest that eCBs may act as mobilizers of HSCs from the bone marrow (BM) under stress conditions as beta-adrenergic receptors (Adrß). This study demonstrates that BM mesenchymal stem cells (MSCs) secrete anandamide (AEA) and 2-arachidonylglycerol (2-AG) and the peripheral blood (PB) and BM microenvironment contain AEA and 2-AG. 2-AG levels are significantly higher in PB of the G-CSF-treated group compared with BM plasma. BM mononuclear cells (MNCs) and CD34+ HSCs express CB1, CB2, and Adrß subtypes. CD34+ HSCs had higher CB1 and CB2 receptor expression in G-CSF-untreated and G-CSF-treated groups compared with MSCs. MNCs but not MSCs expressed CB1 and CB2 receptors based on qRT-PCR and flow cytometry. AEA- and 2-AG-stimulated HSC migration was blocked by eCB receptor antagonists in an in vitro migration assay. In conclusion, components of the eCB system and their interaction with Adrß subtypes were demonstrated on HSCs and MSCs of G-CSF-treated and G-CSF-untreated healthy donors in vitro, revealing that eCBs might be potential candidates to enhance or facilitate G-CSF-mediated HSC migration under stress conditions in a clinical setting.

Growing OXA-23 type strains among carbapenem-resistant Acinetobacter baumannii and tigecycline as an alternate combination therapy.

BACKGROUND/AIM: The increasing prevalence and global spread of difficult-to-treat carbapenem-resistant Acinetobacter baumannii has become a serious problem. The aim of this study is to investigate the resistance patterns and tigecycline sensitivity of carbapenem-resistant A. baumannii strains. MATERIALS AND METHODS: Acinetobacter strains that were carbapenem-resistant and collected mainly from intensive care units were included into this study. The antibiotic sensitivity/resistance of the strains to other antibiotics and tigecycline were noted. Presence of blaOXA-23, blaOXA-48, blaOXA-58, and NDM-1 was investigated by PCR. RESULTS: In total, 44 carbapenem-resistant A. baumannii strains were detected. In addition, 57% (25/44) showed resistance to netilmicin and 2% (1/43) to tigecycline. All of the strains were susceptible to colistin. blaOXA-58 was found only in one (2%) strain while blaOXA-23 was found in 14 (32%) strains. All strains were negative for blaOXA-48 and NDM-1. CONCLUSION: blaOXA-23 was the main resistance pattern in carbapenem-resistant A. baumannii strains. blaOXA-58 was present only in one strain and no blaOXA-48 was found. Tigecycline susceptibility is high and it can be a treatment option for a possible combination therapy of carbapenem-resistant A. baumannii, especially for those for whom colistin is contraindicated because of its toxicity.

Evaluation of periodontal pathogens in amniotic fluid and the role of periodontal disease in pre-term birth and low birth weight.

BACKGROUND: Pre-term birth and/or low birth weight (PTLBW) is a serious problem in developing countries. The absence of known risk factors in ≈ 50% of PTLBW cases has resulted in a continued search for other causes. The aim of this study was to examine the effect of periodontitis on pregnancy outcomes. METHODS: Samples were taken from 50 pregnant women who underwent amniocentesis. Polymerase chain reaction was performed on amniotic fluid samples obtained during amniocentesis and on subgingival plaque samples to determine the presence of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus and Eikenella corrodens. Plaque index, gingival index, bleeding on probing, probing depth and clinical attachment level were evaluated. Medical records were obtained after birth. RESULTS: Social and demographic variables were similar among the Gingivitis (G), Localized Periodontitis (LP) and Generalized Periodontitis (GP) groups. Four subjects gave birth to PTLBW neonates. Campylobacter rectus, T. forsythia, P. gingivalis and F. nucleatum were detected in the amniotic fluid and subgingival plaque samples of three patients who gave birth to PTLBW neonates. The amniotic fluid sample from the fourth patient was not positive for any of the tested pathogens. CONCLUSION: These findings suggest that the transmission of some periodontal pathogens from the oral cavity of the mother may cause adverse pregnancy outcomes. The results contribute to an understanding of the association between periodontal disease and PTLBW, but further studies are required to better clarify the possible relationship.

Panton-Valentine leukocidin and some exotoxins of Staphylococcus aureus and antimicrobial susceptibility profiles of staphylococci isolated from milks of small ruminants.

The aims of this study were to determine the existence of pvl gene, some toxin genes, and mecA gene in Staphylococcus aureus strains isolated from sheep milk and to examine antimicrobial resistance profiles in staphylococci from sheep and goats' milk. The milk samples were collected from 13 different small ruminant farms in Kirikkale province from February to August 2009. A total of 1,604 half-udder milk samples from 857 ewes and 66 half-udder milk samples from 33 goats were collected. Staphylococcus spp. were isolated and identified from the samples. Toxin genes and mecA gene among S. aureus strains were determined by PCR. Antimicrobial susceptibility of staphylococci was examined by the disk diffusion method on Mueller-Hinton agar, and interpreted according to the Clinical Laboratory Standards Institute (CLSI) guidelines. The prevalence of subclinical intramammary infection in both ewes and goats was 5.2%. The most prevalent subclinical mastitis agents were coagulase-negative staphylococci and S. aureus with prevalences 2.8% (n:46) and 1.3% (n = 21), respectively. The prevalence of resistances in isolated Staphylococcus spp. to penicilin G, tetracycline, erythromycin, gentamicin, and enrofloxacin were found as 26.9% (18), 7.5% (5), 6.0% (4), 3.0% (2), and 1.5% (1), respectively. Only 3 of the 21 S. aureus ewe isolates (13.4%) were shown to harbor enterotoxin genes being either seh, sej or sec. However, fourteen (66.6%) of the 21 S. aureus isolates had pvl gene while none of the isolates harbored mecA gene. In conclusion, Staphylococci were shown to be the most prevalent bacteria isolated from subclinical mastitis of ewes and goats and these isolates were susceptible to most of the antibiotics. In addition, S. aureus strains isolated from ewes were harboring few staphylococcal enterotoxin genes. However, Panton-Valentine leukocidin produced by S. aureus could be an important virulence factor and contribute to subclinical mastitis pathogenicity.

[Antimicrobial resistance profiles of Shigella spp. isolated from feces samples in Hacettepe University Ihsan Dogramaci Children's Hospital between 1999-2010]. / Hacettepe Üniversitesi Ihsan Dogramaci Çocuk Hastanesinde 1999-2010 Yillari Arasinda Diski Örneklerinden Izole Edilen Shigella Türlerinin Antibiyotiklere Direnç Profilleri.

The symptoms of infections caused by Shigella spp. are diverse and may change from person to person. The choice of antibiotics as well as the prevention of the loss of fluid and electrolytes are important in the clinical recovery. The local resistance rates to antibiotics should be taken into consideration when planning empirical therapy. The aims of this retrospective study were to detect the in vitro antimicrobial susceptibility of 605 Shigella spp. strains isolated from feces samples of children at Hacettepe University Ihsan Dogramaci Children's Hospital between 1999 and 2010 and to compare the resistance rates by years. Susceptibility to ampicillin, cefotaxime, trimethoprim/sulfamethoxazole (T/S), nalidixic acid, and ciprofloxacin were determined in Mueller-Hinton Agar by disk diffusion method according to CLSI criteria. Among a total of 605 Shigella strains, 526 were identified as S.sonnei, 69 as S.flexneri, nine as S.boydii and one as S.dysenteriae. Resistance rates to ampicillin, cefotaxime, T/S and nalidixic acid were 24.3%, 3.6% 74.2% and 4.6%, respectively. All of the isolates were found susceptible to ciprofloxacin. Antibiotic resistance rates of the isolates did not exhibit any differences between the years. S.dysenteriae was isolated once in 2003 throughout this 12 year survey and the isolate was found susceptible to T/S and ciprofloxacin. A significant yearly decrease was detected in the number of stool cultures and number of Shigella spp. isolated in stool (p< 0.001). Ampicillin resistance was higher in S.flexneri (77.8%) and S.boydii (62.5%) than S.sonnei (17%). However, T/S resistance was higher in S.sonnei (78.9%) than S.flexneri (52.5%) and S.boydii (11.1%). In conclusion, continuous surveillance of resistance among Shigella species in Turkey seems to be imperative for establishing empirical treatment guidelines in our country.

[Epidemiological and molecular characteristics of hospital-acquired methicillin-resistant Staphylococcus aureus strains isolated in Hacettepe University Adult Hospital in 2004-2005]. / Hacettepe Üniversitesi Eriskin Hastanesinde 2004-2005 yillarinda izole edilen hastane kaynakli metisiline dirençli Staphylococcus aureus suslarinin epidemiyolojik ve moleküler özellikleri.

The aim of this study was to determine the epidemiological and molecular characteristics of hospital-acquired (HA)-methicillin-resistant Staphylococcus aureus (MRSA) isolates by investigating the distribution of clinical samples according to the hospital wards, antibiotic susceptibility patterns, staphylococcal chromosome cassette mec (SCCmec) types and the presence of Panton-Valentine Leukocidin (PVL) genes. A total of 110 MRSA isolates obtained from various clinical samples of inpatients at Hacettepe University Adult Hospital between January 2004 and December 2005 were included in the study. The identification of the isolates was done by BD Sceptor automated system (Becton Dickinson, USA). The mecA gene, SCCmec types and PVL genes were detected by polymerase chain reaction (PCR). Pulsed field gel electrophoresis (PFGE) was performed to examine the clonal relatedness. The susceptibility testing was performed for some antibiotics by E-test (AB Biodisk, Sweden) and for the others by disk diffusion methods according to the Clinical and Laboratory Standards Institute (CLSI) recommendations. The clinical samples (35 blood, 37 pus, 23 deep tracheal aspiration, 5 catheter, and 10 other samples) that yielded the MRSA strains were isolated from patients (71.5%) at intensive care units and surgical wards. All the isolates were positive for mecA gene. Of the isolates, 68 (61.8%) were harboring SCCmec type III, 38 (34.5%) SCCmec variant IIIB, and 3 (2.7%) SCCmec type IV. One isolate which was mecA gene positive could not be classified in any of the SCCmec types. PVL was positive in 14 (12.7%) of the isolates. All MRSA strains were susceptible to tigecycline, linezolid, vancomycin and teicoplanin; however, exhibited high rates (> 90%) of resistance to gentamicin, ciprofloxacin and rifampin. Susceptibility rates to trimethoprim/sulfamethoxazole was 90%, clindamycin 53% and erythromycin 32%. Eight pulsotypes were distinguished on the basis of PFGE (A, B, C, D, K, L, N, O). Of the total isolates, 92.7% belonged to pulsotype A. HA-MRSA strains predominantly isolated from pus and blood samples of inpatients at intensive care units and surgical wards in our hospital were multi-resistant. Majority of these isolates were SCCmec III, or variant IIIB type. Although PVL is known as a common virulence factor of community-acquired MRSA, HA-MRSA isolates in our center have a considerable rate of PVL positivity pointing out the importance of surveillance of the changing epidemiology of MRSA.

Galactomannan on the stage: prospective evaluation of the applicability in routine practice and surveillance.

Invasive aspergillosis (IA) presents a diagnostic and therapeutic dilemma for the physicians who take care of the patients with severe underlying diseases and immunosuppression. This study aimed to evaluate the usefulness of serum galactomannan (GM) measurements in the routine practice and surveillance of IA along with possible caveats in diagnosis and treatment. Adult patients with high-risk haematological malignancies admitted to the Internal Medicine wards during the 2-year study period were followed up by daily visits for vital signs, existing or newly developing signs and symptoms, clinical and laboratory findings. Blood samples were analysed for GM levels by the ELISA method at the end of the study period. Data of 58 hospitalisation episodes in 45 patients were analysed. Proven IA was diagnosed in one patient, probable IA was diagnosed in four patients. The sensitivity was 60% and the specificity was 21% when the index cut-off for positivity was accepted as 0.5. The yield of GM testing may be influenced by many variables and each centre should evaluate the usefulness of this test in its own conditions.

A Chryseobacterium meningosepticum outbreak observed in 3 clusters involving both neonatal and non-neonatal pediatric patients.

Three clusters of Chryseobacterium meningosepticum infections in a tertiary health center in July 2006 and January 2007 involving 8 newborns and 5 older children were investigated. The index patient was from the neonatal intensive care unit, and the older patients were from other pediatric wards. Cultures were obtained from the environment and from health care workers' hands as part of an outbreak investigation. C meningosepticum was isolated from hand cultures obtained from a senior resident and from environmental cultures obtained from powdered infant formula, an electrical button, a computer keyboard, phone, a doorknob, and an Ambu bag. Antibiogram typing and enterobacterial repetitive intergenic consensus sequence polymerase chain reaction indicated that all of the isolates were epidemiologically related. Nine patients improved on antimicrobial treatment, and 4 premature infants died after the infection. C meningosepticum is a well-known etiologic agent for nosocomial infections involving newborns and immunocompromised patients. Wet and dry environmental surfaces and equipment may act as a source or play a role in disseminating the microorganism. Outbreaks may be controlled with strong emphasis on infection control measures.

First vancomycin-resistant blood isolate of Enterococcus faecium in a children's hospital and molecular analysis of the mechanism of resistance.

The first clinical isolate of vancomycin-resistant Enterococcus spp. in Hacettepe University Children's Hospital was isolated from a blood culture of a patient hospitalized in the intensive care unit. He had been on vancomycin therapy for the last four months for consecutive pneumoniae and sepsis. The isolate was identified as Enterococcus faecium (E. faecium) and minimal inhibitor concentration (MIC) values were determined as >256 microg/ml and 256 microg/ml for vancomycin and teicoplanin, respectively, with E-test. The isolate was shown to carry the vanA gene with polymerase chain reaction (PCR). Twelve colonizing strains were isolated from the surveillance cultures during the same period and identified as E. faecium, and were also shown to carry the vanA gene. However, arbitrarily-primed-PCR and pulsed-field gel electrophoresis results could not confirm the source of the resistant strain nor did they suggest a clonal spread in the hospital.

[The frequency of PER-1 type extended spectrum beta-lactamases in nosocomial isolates of Pseudomonas aeruginosa]. / Hastane kaynakli Pseudomonas aeruginosa izolatlarinda PER-1 türü genislemis spektrumlu beta-laktamaz enzimlerinin sikligi.

The aim of this study was to determine the frequency of PER-1 type extended-spectrum beta-lactamase (ESBL) in nosocomial Pseudomonas aeruginosa strains isolated in Hacettepe University Adult Hospital. Sixty-seven non-duplicate P. aeruginosa isolates from patients with nosocomial infections between January 2002 and December 2004 were included in the study. The isolates were identified at species-level by Sceptor (Becton Dickinson, USA) system, and all the strains were stored at -80 degrees C until further testing. Polymerase chain reaction (PCR) was performed for the detection of (bla)PER-1 genes, and PFGE analysis was used to investigate their genetic relatedness. The antimicrobial susceptibilities of the PER-1 positive isolates were determined by Etest (AB Biodisk, Solna, Sweden) method. According to the results of PCR, 22.7% (15/67) of the isolates were positive for PER-1 enzyme. Those 15 (bla)PER-1 positive isolates showed eight different PFGE patterns, indicating the presence of multiple clones. Of the PER-1 positive P. aeruginosa isolates, nine were resistant to imipenem/meropenem, and 11 were resistant to piperacillin-tazobactam and tobramycin. The epidemiological investigation of multidrug resistant P. aeruginosa should give important clues for the initial empirical therapy, especially in certain geographic locations where ESBL-producing P. aeruginosa strains seemed to be highly prevalent.

[Investigation of herpes group and hepatitis A virus nucleic acids in the atherome plaque samples of patients with coronary arterial disease]. / Koroner arter hastalarinin aterom plagi örneklerinde herpes grubu ve hepatit A viruslarina ait nükleik asit varliginin arastirilmasi.

It is assumed that various infectious agents play direct or indirect roles in the pathogenesis of atherosclerosis which is accepted as a chronic inflammatory phenomenon. However, the data obtained from different studies are contradictory. The aim of this study was to investigate the roles of herpes virus group [Herpes simplex virus (HSV), Epstein-Barr virus (EBV), Cytomegalovirus (CMV)] and hepatitis A virus (HAV) which are debated in terms of their impact in the pathogenesis of coronary arterial diseases. For this purpose, atherome plaque samples collected from 28 patients (23 were male; age range: 43-74 years) with atherosclerotic heart disease and vein samples from 22 control patients (19 were male; age range: 37-85 years) who had vascular diseases other than atherosclerosis, were investigated by means of the presence of nucleic acids of the above mentioned viruses by real-time polymerase chain reaction (PCR). Besides, classical cardiovascular risk factors (hypertension, hyperlipidemia, hypercholestrolemia, diabetes mellitus, smoking habits, gender, age and familial background) were questioned in both patient and control groups. As a result, no positivity were detected for nucleic acids of HSV type 1 and 2, EBV and HAV, whereas CMV-DNA was found positive in three of 28 (10.7%) atheromateous plaques (viral loads were 21, 188 and 288 copies/mg). Amongst 22 vascular samples from controls, two (9.1%) yielded positive results for EBV-DNA (viral loads were 5 and 10 copies/mg), while the other samples were found negative for nucleic acids of HSV type 1 and 2, CMV and HAV. The evaluation of the known risk factors for atherosclerosis revealed that, the difference between the presence of hypertension and hyperlipidemia which are the major risk factors, was statistically important (p < 0.05) in patient group (64% and 50%, respectively) and control group (32% and 23%, respectively). In conclusion, the hypothesis concerning the possible relationship between these viral agents and the progression of atherosclerosis, have not been supported by our data which are similar to the results obtained from various other studies. Actually, further studies are needed to clarify such direct or indirect roles of infectious agents in the pathogenesis of coronary arterial diseases.

[Case report: a nosocomial infection caused by vancomycin resistant enterococcus]. / Olgu sunumu: vankomisine dirençli enterokoka bagli bir hastane enfeksiyonu.

Vancomycin resistant enterococcus (VRE) was recovered from the urine culture of a 61 years old female patient, who was being treated for sepsis, on the 15th day of hospitalization in Ondokuz Mayis University Hospital Infectious Disease Unit. The underlying diseases of this patient were chronic renal failure and diabetes mellitus. The patient died due to septic shock on the day of VRE isolation. Since this case was the first VRE infection in our hospital, a point prevalence study was planned. For this purpose, rectal swab samples collected from 10 patients from the same unit and 27 personnel who worked in the same unit, were screened for the presence of VRE. Nasal swabs and finger tip samples were also taken from the staff to determine if the transmission has occured in this way. As a result, a second VRE strain was isolated from another patient with chronic renal failure who was under treatment due to multiple pulmonary abscesses. Immediate isolation of this patient prevented a possible epidemic in this specific unit. In this report, the importance of VRE screening and isolation of the patients after the recovery of VRE has been emphasized.

False positivity for Aspergillus antigenemia related to the administration of piperacillin/tazobactam.

BACKGROUND: Invasive aspergillosis is a challenge to the internist, and difficulties diagnosing the disease remain an everlasting problem. METHODS: We reviewed the data of 65 patients with hematological malignancies and aplastic anemia who were tested for the galactomannan (GM) antigen of Aspergillus between March and November 2003. RESULTS: GM antigen levels were false-positive in at least two consecutive samples in 5 out of 23 patients who did not have evidence of invasive aspergillosis (false positivity rate of 21.7%) but who received concomitant piperacillin/tazobactam (P/T) compared to 0 of 28 patients who did not. DISCUSSION: The use of P/T in febrile, neutropenic patients decreases the specificity of GM antigen testing, which may lead to incorrect and unnecessary attempts at diagnosis and therapy.

A cluster of nosocomial Klebsiella oxytoca bloodstream infections in a university hospital.

BACKGROUND: On February 19, 2003, four patients (patients 1-4) in the neurology ward underwent cranial magnetic resonance angiography (MRA) and developed fever within 1 hour afterward. Klebsiella oxytoca was isolated from blood cultures of patients 1 through 3. OBJECTIVE: To identify the source of this cluster of nosocomial K. oxytoca bloodstream infections. DESIGN: Outbreak investigation. SETTING: A 1,000-bed university hospital. METHODS: The infection control team reviewed patient charts and interviewed nursing staff about the preparation and administration of parenteral fluids. The procedure of cranial MRA was observed. Arbitrarily primed polymerase chain reaction (AP-PCR) was performed to show the clonal relationship among these three strains. RESULTS: AP-PCR revealed that three K. oxytoca isolates had the same molecular profile. Cranial MRA was found to be the only common source among these patients. During MRA, before injection of the contrast medium, normal saline solution was infused to check the functioning of the intravenous catheter. Use of the solution for multiple patients was routine, but the access diaphragm of the bottle was not cleansed. The bottle of normal saline solution used on February 19 had already been discarded and the culture sample taken from the solution on the day of observation was sterile. CONCLUSIONS: We speculate that normal saline solution became contaminated during manipulation and that successive uses might have been responsible for this cluster. Poor aseptic techniques employed during successive uses appear to be the most likely route of contamination. Use of parenteral solutions for multiple patients was discontinued.